Packaging machines have been developed for handling dry granular materials, such as sand, gravel, fertilizer, sugar, beans, grains, and other flowable foodstuffs. It is common practice to pack the materials in hard surface containers or in cloth, paper, or plastic sacks, with the granular materials being loaded through the open end of the sack, etc., with the open end of the sack later being stitched, glued, or otherwise sealed shut.
My prior U.S. Pat. No. 5,752,367 discloses an automated apparatus for packaging generally granular materials, which includes two or more fill hoppers which are alternately positioned beneath a central feed hopper and which move laterally to a delivery position to discharge the materials received therein. This system includes a gravity actuated trap door carried by each fill hopper which is opened in response to the fill hopper reaching the discharge position, to allow the material to flow from the fill hopper to the receiving sack or other container. While my foregoing system is successful in delivering most flowable solid materials, the system does not function as well when handling fine grain particles, such as fine sand or other granular materials of the size and shape of fine sand. In some instances, particularly when the material is wet, the function of the trap doors of such a system can be impeded by the wet material. In some instances the material is not properly discharged from the fill hoppers and some of the material clings to and accumulates between the trap doors and the bottom edge of the reciprocating fill hopper.
Thus, there is a need for an improved system for reliably and expediently loading containers with flowable granular materials that is less subject to the flowable material accumulating between the parts of the dispensing apparatus and impeding the dispensing function of the system.